Acting Prime Minister Kelvin Davis joined The AM Show on Tuesday, and said it's going to be "very traumatic" but "we have to face up to this part of our history".

"Your heart goes out to these people," he told host Duncan Garner.

"You can just see how the trauma these people experienced either in state care or in these faith-based institutions has had a massive impact on their life and subsequent generations. And I think it's time as a country that we faced up to what we've done."

Mr Davis said commission process needs to be completed first before looking at whether charges should be laid.

"I think people should be held to account for any abuse or offense that they commit whether it's here as part of this commission or just out in the community," he says.

"There'll be some people that are sitting back going 'oh crikey, I was part of that abuse' and I think they should be a, ashamed, but worried about what the future may hold."

Speaking from the churches' perspective is Anglican Archbishop Philip Richardson, who said it's "inconceivable" there hasn't been some abuse within church institutions.

"There was, as the Prime Minister has said, a dark chapter in New Zealand's history," he told Garner.

"The churches stand ready to be part of that scrutiny and we welcome it."

The archbishop has personally heard less than five complaints, but estimates there could be a couple of dozen of victims from Anglican institutions - and possibly "significantly more".

"We simply don't have a handle on what the numbers might be."

And he says those involved in any abuse or cover-up need to be "held accountable".

"If there's criminal behaviour... there are appropriate means for remedy and they must be followed," he says.

"Certainly if a church member... has been responsible for criminal activity, that's something that the police will be asked to deal with."